Preface - Practical and theoretical considerations for performing a multi-center preclinical biomarker discovery study of post-traumatic epileptogenesis: lessons learned from the EpiBioS4Rx consortium.

The Epilepsy Bioinformatics Study for Antiepileptogenic Therapy (EpiBioS4Rx) is a NINDS funded Center-Without-Walls international study aimed at preventing epileptogenesis after traumatic brain injury (TBI). One objective of EpiBioS4Rx relates to preclinical biomarker discovery for post-traumatic epilepsy. In order to perform a statistically appropriately powered biomarker discovery study, EpiBioS4Rx has made a rigorous attempt to harmonize the preclinical procedures performed at the three EpiBioS4Rx centers, located in Finland, Australia, and the USA. Moreover, we have also performed a rigorous interim analysis of the success of procedural harmonization, which is reported in this virtual special issue. The analysis included harmonization of the production of animal model, blood sampling, electroencephalogram analyses (seizures, high-frequency oscillations) and magnetic resonance imaging analysis. Based on lessons learned, we propose a 3-stage protocol to facilitate the success of preclinical multicenter studies: preparation ⇨ testing ⇨ multicenter study. The need of funding for preparation and testing phases, which precede the actual multicenter study and are necessary for its success, should be taken into account in the design of funding schemes.